Damping Characteristics of Fluidic Pressure-fed Mechanism for Positioning Applications

This paper represents a novel approach capable of in-process damping parameter control for nanopositioning systems by implementing a fluidic pressure-fed mechanism (FPFM). The designed internal fluidic channels inside the nanopositioning stage fabricated by a metal additive manufacturing process can be filled with various fluids such as air, water, and oil and pneumatically or hydraulically pressurized. The damping was experimentally characterized with respect to fluids and corresponding pressure level (80 psi) through free-vibration tests, hammering test, and sine input sweeping test in open-loop and closed-loop positioning control conditions. As a result, the FPFM revealed the following characteristics: (1) damping may increase when the internal fluidic channels filled with fluids and pressure level at 80 psi, (2) the dynamic system showed the highest damping when the water exists in internal channels, (3) the existence of fluids and certain pressure in the fluidic channel does not have a significant influence on the motion quality and positioning control, but tracking error was reduced by FPFM. It is expected that the FPFM method will be utilized for vibration and noise control applications for high precision dynamic systems.